This invention relates generally to a food product slicer of the type having a rotatable circular or disc-like slicing knife, a gauge plate along one edge of the knife for determining the thickness of slices and a carriage, generally perpendicular to the face of the knife, for supporting food product as it is moved past the cutting edge of the knife during slicing. The invention relates to a means for guarding the periphery of the knife in combination with a knife sharpener carried by a portion of the guarding means. The guard is mounted on the slicing machine in a fashion which prevents removal thereof except under conditions where the knife itself is first removed. The invention additionally relates to a specific knife sharpener which can be easily moved between an inactive position and an active sharpening position and easily removed from the sharpener supporting means for cleaning remote from the machine, all with one hand. The sharpener is mountable on a portion of the means which supports the knife edge guard to provide for ease of manufacturing and accuracy of positioning the sharpener relative to a relieved or notched portion of the knife edge guard.